Consolidation and restructuring of the U.S. health care sector has resulted in the growth of large health networks and health systems that differ in their ownership arrangements and inter-organizational structure. Whether differences in organizational factors within health networks and health systems affect the level of clinical integration and quality achieved by member hospitals is not well understood. The goal of this study is to determine the effects of variation in ownership arrangements and inter- organizational structure of health networks and health systems on the level of clinical integration and quality indicators at the hospital level. Additionally, the study provides new evidence on the relationship between clinical integration and quality at the hospital level. With the recent availability of new data and methods that provide: l) more fine grained classification of the inter-organizational relationships in health networks and health systems, 2) objective measurement of clinical integration across a wide sample of hospitals, and 3) risk-adjusted quality indicators at the hospital level, this study represents one of the first opportunities empirically test the effectiveness of alternative delivery arrangements on the ability to achieve two of the chief claims of consolidation: clinical integration and quality improvement. The conceptual framework is grounded in inter-organizational and network theory to develop hypotheses regarding the relationship between health network and health system structure and performance. The findings will l) advance our knowledge about the relationship between organizational structure and performance, and 2) provide meaningful data on health care quality will inform consumers, purchases, providers and policy makers on the relative benefits and costs of receiving, purchasing, providing and promoting care in alternative multi-institutional arrangements.